condition mean min max ZT0-3 8.525848 8.525848 8.525848 ZT4-7 12.694787 12.694787 12.694787 ZT8-11 12.4357615 12.4357615 12.4357615 ZT12-15 11.353199 11.353199 11.353199 ZT16-19 11.001702 11.001702 11.001702 ZT20-23 10.396677 10.396677 10.396677